A team of researchers coordinated by astrophysicist David Harvey, from the Federal Polytechnic School of Lausanne, in Switzerland, has discovered that the enigmatic dark matter that makes up much of the cosmos interacts with itself even less than previously suspected .
To determine this, they have studied how what is believed to be present in galactic clusters, superstructures made up of tens or hundreds of galaxies, behaves when they come into contact with each other.
In a study published in the journal Science based on observations made with the Hubble and Chandra space telescopes, the latter of X-rays, these astronomers explain that this lack of interaction could make it easier for scientists to unravel their true nature .
At present, it is estimated that dark matter could make up about 22% of everything in the universe . About 74% remaining would correspond to an equally unknown force called dark energy, and only 4% would be visible matter , for example gas clouds, stars, planets … Although there is more dark matter than visible in the cosmos, it is extraordinarily difficult to detect, as it does not reflect, absorb or emit light.
In essence, it is invisible to us. We know about it only by the gravitational effect it exerts on matter that we can see . This is precisely the reason why these experts have decided to study collisions in galactic clusters, since dark matter intervenes in them naturally and is present in large quantities.
“We know how both gas and stars behave during these events and how they emerge from them. If we can compare it with what happens to dark matter, we will be closer to knowing what it is, ”says David Harvey. Now, the group he leads has found that these violent encounters between galaxies, which occur over hundreds of millions of years, do not slow down dark matter .
But this does not happen because the particles that supposedly make it up are very far apart from each other – in fact, the most widespread hypothesis among astrophysicists is that they are very close together – but because they do not seem to relate much to each other – for For example, they might be expected to collide with each other and fly off – as little at least as they do with visible matter.
